Theoretical study of coexistence of ordering and spinodal decomposition

According to the conventional theory of solid solutions (the nearest neighbor atomic interaction model), ordering and spinodal decomposition/clustering are mutually exclusive processes. However, it has been found that the coexistence of ordering and spinodal decomposition (COSD) occurs in a large number of alloys. This fact gave a strong challenge to the conventional theory. A statistical investigation revealed that the COSD was closely related to large atomic-size factors. It was thus proposed that the COSD stemmed from the long-range elastic interactions due to atomic-size disparity. In order to verify this idea, the formulism of concentration waves was applied to calculating the elastic interactions. The results proved that long-range atomic elastic interactions promoted both ordering and spinodal decomposition. A possible application of the COSD reaction was proposed, i.e. using this reaction to fabricate high-performance "natural nano-alloys".